Electric motor



Feb. 4, 1941. R, AVlGDoR 2,230,581

ELECTRIC MOTORl Filed ot. 1'7, 195s Patented Feb. 4, 1941 UNITED STATES PATENT OFFICE Application October 17, 1938, Serial No. 235,523 In Germany July 15, 1938 4 Claims.

The invention relates to electromotors adapted to be built in which are preferably used in plunging pump sets. The object of the invention is to provide for means enabling to mount and to remove the electromotor in or from a casing or some special housing in an easy and simple manner, without being compelled to loosen the lines supplying the electric current to the motor.

According to the invention the electric connection between the supply-lines and the electromotor is obtained on the one hand by a set of contacts, mounted on the electromotor and on the other hand by a set of contacts mountedon the casing or the container, which sets of contacts, when building-in the electromotor, are brought into contact with each other. Preferably the one set of contacts is arranged on the end of the .electromotor directed towards the motor receiving casing, whereas the other set of contacts is mounted on a transverse partition of the tubular motor receiving casing. The contacts on the electromotor are preferably constructed as spring-contacts, whereas the contacts on the motor receiving casing constitute concentric rings or discs.

Plunging-pump sets are also used for feeding readily iniiammable and explosive power-mediums. In pump sets of this type it may happen that the electric supply-line is still closed when the mounting or dismounting of the motor takes place. When opening or closing the contacts there is danger of explosion in connection with the formation of sparks in the immediate vicinity of the power-medium. The space in which the sets of contacts are located is in itself closed by a seal with respect to the power-medium. Now, according to the invention, when using a seal between the electromotor and the motor receiving casing, the construction is preferably such, that when removing the electromotor from its casing the contacts are opened before the seal is made inoperative, whereas when mounting the electromotor the contacts are brought into engagement with each other only after the space in which the contacts arc located has been completely sealed from the exterior by the seal.

The ligure of the drawing is an elevational View with parts in section.

The invention will be more fully understood with reference to the drawing, illustrating it schematically by way of example.

I denotes the electromotor and 2 a portion of the casing in which the electromotor is built-in. The attachment of the electromotor to the motor receiving casing is effected by means of screwthread 3 on a ring portion at the outer side of the motor casing and on the lower end of the motor receiving casing 2.

On the bottom of a recess in the casing 2 an insulating plate 4 is secured. This plate carries a contact ring 5 and in the centre a contact disc 6. The contact ring is connected to a terminal 1 and the contact disc to a terminal 8. From both terminals the current supply line 9 passes outwards through a tube I0. At the end of the electromotor directed towards the two contacts referred to above two spring contacts I I and I2 are mounted. The spring contact II comes into engagement with the centrally located contact disc 6 when the electromotor is built-in, whereasl the spring contact I2 comes into engagement with the contact ring 5. It appears from the drawing that in this manner the electromotor may be built-in and removed without loosening the current supply lines. It further appears that when screwing out the electromotor I from the .casing 2 the contacts are opened, but that the built-in seal I3 still remains operative, i. e. completely seals the contact space from the exterior. The seal I3 may consist of natural or synthetic rubber or any other elastic, but non-plastic mass. Only when the screwthread connection has been loosened and the electromotor is withdrawn from the casing, the contacts are exposed to the atmosphere.

I claim:

1. A contact sealing arrangement for electromotors comprising an electromotor, a casing therefor, a sealing casing, means releasably connecting said casing and said sealing casing, sealing means between said casings and cooperating contacts on said casings shielded from the exterior by said casings and protected by said sealing means so that all breaks between said contacts take place before said sealing means become ineffective upon separating said casing from said sealing casing and all makes take place after said sealing means become effective upon connecting said casing to said sealing casing.

2. An arrangement as set forth in claim 1 in which the contacts on said casing are directed towards said sealing casing and the contacts on said sealing casing are mounted in al transverse partition of said sealing casing.

3. An arrangement as set for-th in claim 1 in which the contacts on said casing are spring contacts and one of the contacts in said sealing casing is a concentric ring.

4. An arrangement as set forth in claim 1 in which the contacts on said casing are spring contacts and one of the contacts in said sealing casing is a disc.

RIFAT AVIGDOR. 

